Turbine apparatus



Ap il 16, 1940. J. c BQ HAN 2,197,334

TURBINE APfijARAT s Filed Sept. {14, 1938 INVENTOR BY W Tb,

ATTORNEY ,Jdgzpu 0.50am

Patented Apr. 16, 1940 UNITED STATES 2,197,334 TURBINE APPARATUS JosephC. Bohan, Prospect Park, Pa., assignor to Westinghouse Electric &Manufacturing Company, East Pittsburgh, Pa., a corporation ofPennsylvania.

Application September 14, 1938, Serial No. 229,814 3 claims. (01.253-77) My invention relates to shrouded turbine blading and it has foran object to provide a tenon and shroud connection permitting of the useof a relatively thick shroud.

A further object of my invention is to provide blades with tenons whichare tapered radially outward to receive a shroud strip having taperedopenings formed to fit the tenons, the strip having such arcuate lengththat planes normal to the plane of rotation and tangent to the outersides of the outer openings are parallel or converge outwardly with theresult that, irrespective of shroud thickness, the tenon openings may beformed to fit the tenons and to permit as- I sembly withoutinterference.

These and other objects are elfected by my invention as will be apparentfrom the following description and claims taken in connection with theaccompanying drawing forming a part of this application, in which:

Fig. 1 is an exploded view, in side elevation and partially in section,of the invention;

Fig. 2 is a side elevational view, partially in section, showing ashroud strip partially connected in assembled relation to its blade;and,

Fig. 3 is a top plan view of the structure-shown in Fig. 2.

Referring now to the drawing more in detail there is shown, at l0, aninner supporting member having an arcuate outer periphery Illa, fromwhich periphery a plurality of turbine blades or brackets ll extendradially outward. These blades may be attached to the supporting memberII! in any well known manner.

The outer free ends of the blades are provided with radially outwardlyextending tenons I2 concentrically tapered towards their outer ends. Theouter ends of the blades are braced by means of a relatively thickshroud ring l3 comprised by segments l l having openings I5 therein forthe reception of the blade tenons i2. These tenons are tapered outwardlytowards the ends and the openings l5 of the'shroud segments M arecomplementally tapered to provide for a relatively close fit of thetenons in the openings.

In the arrangement shown in the drawing, each shroud ring segment isassociated with a group of five blades, the cord of the segments havingan angle of approximately 14 degrees. Each blade tenon has an includedangle of taper of 14 degrees, corresponding to the angle of the cord ofthe segments. Expressed another way, the outermost walls of the outeropenings of each shroud segment are substantially parallel, whereby theshroud ring segments may be readily assembled on the tenons with thelatter filling the openings and without interference. If the shroud ringsegments should be of such length as to include a greater number ofblades, 5 defining a greater angle, then the tenons will have anincluded angle of taper corresponding to this greater angle.

Preferably, the tenons are of such length as to extend beyond the outerperipheral surface 10 of the shroud ring so that the excess materialprojecting therebeyond may be deformed, as by peening or spinning, toprovide heads l6 securely retaining the blades and shroud ring inassembled relation.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications without departing from thespirit'thereof, and I desire, 20 therefore, that only such limitationsshall be placed thereupon as are imposed by the prior art or as arespecifically set forth in, the appended claims.

What I claim is:

1. In a turbine, a supporting member having an arcuate periphery, bladesextending radially outwardly from-the periphery of said supportingmember, tenons extending radially outwardlyfrom the outer ends of theblades and a rela- 80 tively thick segmental shroud ring having holesfor passage therethrough of the tenons, said tenons being.concentrically tapered towards their outer ends'and the holesin theshroud ringbeing complementally tapered, the included an- 35 gle oftaper of each tenon being notless than the angle of the cord of thesegments, whereby the shroud ring segments may be freely assembled onthe radially extending tenons.

2. In a turbine, a supporting member having 40 anarcuate periphery,blades extending radially outwardly from the periphery of saidsupporting member, tenons extending. radially outwardly from the outerends of the blades and a relatively thick segmental shroud ring havingholes 45 for passage therethrough of the tenons, said tenons beingconcentrically tapered towards their outer ends and the holes in the'shroud'ring being complementally tapered, the included angle of taperof each tenon being not less than the angle of the cord of the segmentsand the outer ends of the tenons extending beyond the. outer surface ofthe shroud ring and being peened over thereagainst.

3. In a turbine, a supporting member having ring segments beingcomplementally tapered, the taper being of such degree that the twoendmost walls of the openings of each segment are substantiallyparallel, whereby the shroud ring segments may be freely assembled onthe 5 tenons by purely rectilinear movement.

JOSEPH C. BOHAN.

